While global patterns of human genetic diversity are increasingly well characterized, the diversity of human languages remains less systematically described. Here, we outline the Grambank database.... Show moreWhile global patterns of human genetic diversity are increasingly well characterized, the diversity of human languages remains less systematically described. Here, we outline the Grambank database. With over 400,000 data points and 2400 languages, Grambank is the largest comparative grammatical database available. The comprehensiveness of Grambank allows us to quantify the relative effects of genealogical inheritance and geographic proximity on the structural diversity of the world’s languages, evaluate constraints on linguistic diversity, and identify the world’s most unusual languages. An analysis of the consequences of language loss reveals that the reduction in diversity will be strikingly uneven across the major linguistic regions of the world. Without sustained efforts to document and revitalize endangered languages, our linguistic window into human history, cognition, and culture will be seriously fragmented. Show less
Leptin is a hormone that plays a key role in controlling food intake and energy homeostasis. Skeletal muscle is an important target for leptin and recent studies have shown that leptin deficiency... Show moreLeptin is a hormone that plays a key role in controlling food intake and energy homeostasis. Skeletal muscle is an important target for leptin and recent studies have shown that leptin deficiency may lead to muscular atrophy. However, leptin deficiency-induced structural changes in muscles are poorly understood. The zebrafish has emerged as an excellent model organism for studies of vertebrate diseases and hormone response mechanisms. In this study, we explored ex-vivo magnetic resonance microimaging (μMRI) methods to non-invasively assess muscle wasting in leptin-deficient (lepb-/-) zebrafish model. The fat mapping performed by using chemical shift selective imaging shows significant fat infiltration in muscles of lepb-/- zebrafish compared to control zebrafish. T2 relaxation measurements show considerably longer T2 values in the muscle of lepb-/- zebrafish. Multiexponential T2 analysis detected a significantly higher value and magnitude of long T2 component in the muscles of lepb-/- as compared to control zebrafish. For further zooming into the microstructural changes, we applied diffusion-weighted MRI. The results show a significant decrease in the apparent diffusion coefficient indicating increased constraints of molecular movements within the muscle regions of lepb-/- zebrafish. The use of the phasor transformation for the separation of diffusion-weighted decay signals showed a bi-component diffusion system which allows us to estimate each fraction on a voxel-wise basis. A substantial difference was found between the ratio of two components in lepb-/- and control zebrafish muscles, indicating alterations in diffusion behavior associated with the tissue microstructural changes in muscles of lepb-/- zebrafish as compared to control zebrafish. Taken together, our results demonstrate that the muscles of lepb-/- zebrafish undergo significant fat infiltration and microstructural changes leading to muscle wasting. This study also demonstrates that μMRI provides excellent means to non-invasively study the microstructural changes in the muscles of the zebrafish model. Show less
Leptin is a hormone that plays a key role in controlling food intake and energy homeostasis. Skeletal muscle is an important target for leptin and recent studies have shown that leptin deficiency... Show moreLeptin is a hormone that plays a key role in controlling food intake and energy homeostasis. Skeletal muscle is an important target for leptin and recent studies have shown that leptin deficiency may lead to muscular atrophy. However, leptin deficiency-induced structural changes in muscles are poorly understood. The zebrafish has emerged as an excellent model organism for studies of vertebrate diseases and hormone response mechanisms. In this study, we explored ex-vivo magnetic resonance microimaging (& mu;MRI) methods to non-invasively assess muscle wasting in leptin-deficient (lepb(-/-)) zebrafish model. The fat mapping performed by using chemical shift selective imaging shows significant fat infiltration in muscles of lepb(-/-) zebrafish compared to control zebrafish. T-2 relaxation measurements show considerably longer T-2 values in the muscle of lepb(-/-) zebrafish. Multiexponential T-2 analysis detected a significantly higher value and magnitude of long T-2 component in the muscles of lepb(-/-) as compared to control zebrafish. For further zooming into the microstructural changes, we applied diffusion-weighted MRI. The results show a significant decrease in the apparent diffusion coefficient indicating increased constraints of molecular movements within the muscle regions of lepb(-/-) zebrafish. The use of the phasor transformation for the separation of diffusion-weighted decay signals showed a bi-component diffusion system which allows us to estimate each fraction on a voxel-wise basis. A substantial difference was found between the ratio of two components in lepb(-/-) and control zebrafish muscles, indicating alterations in diffusion behavior associated with the tissue microstructural changes in muscles of lepb(-/-) zebrafish as compared to control zebrafish. Taken together, our results demonstrate that the muscles of lepb(-/-) zebrafish undergo significant fat infiltration and microstructural changes leading to muscle wasting. This study also demonstrates that & mu;MRI provides excellent means to non-invasively study the microstructural changes in the muscles of the zebrafish model. Show less
